Optical spectroscopy is a non-invasive diagnostic technique that employs light for quantitative characterisation of tissue optical properties (scattering, absorption, fluorescence), related to morphological, functional and biochemical changes in tissue. Main advantages of optical spectroscopy are: 1) it is safe due to the use of non-ionizing irradiation, 2) it is patient-friendly due to its non-invasive character, and 3) it is inexpensive and easy-to-use due to the device simplicity, making it suitable for point-of-care settings. Optical spectroscopy has shown promise for many aspects of cancer management, including screening, diagnosis, image-guided surgery, and therapy monitoring. Recent literature shows that biomarkers of field carcinogenesis can be optically assessed in visually normal tissues; these findings suggest that it would be possible to assess an individual’s risk for developing cancer through the analysis of normal-appearing tissue from an easily accessible location, paving the way towards novel pre-screening strategies using non-invasive optical technologies. TNO has developed an optical spectroscopy device to measure these optical biomarkers of field carcinogenesis, and the feasibility of the approach is currently demonstrated in the Erasmus MC on selected patients with lung cancer, esophageal cancer and head and neck (H&N) cancer and age-matched controls.